Method, system, device and medium for detecting combustible gas concentration in low-temperature storage tank area

Abstract

The application provides a combustible gas concentration detection method, system, device and medium for a low-temperature tank area. The method comprises the following steps: arranging combustible gas detection units in a tank top monitoring area of the low-temperature tank area based on a preset arrangement strategy; acquiring combustible gas concentration detection data output by the combustible gas detection units in a preset detection period; determining a combustible gas risk state of the tank top monitoring area according to the combustible gas concentration detection data; and generating a combustible gas concentration detection result of the low-temperature tank area according to the combustible gas risk state. The method can improve the coverage of cold heavy gas layering through comprehensive monitoring at multiple heights, and can reliably detect slow volatile gas that is originally missed by a single height and a small number of points, thereby accurately reflecting the real combustible gas risk state of the tank top space of the low-temperature tank area in a timely manner.

Description

Technical Field

[0001] This application relates to safety detection technology, and more particularly to a method, system, equipment and medium for detecting the concentration of combustible gas in a cryogenic storage tank area. Background Technology

[0002] For cryogenic tank areas, such as LNG full-containment tanks, the top space of the tank is usually equipped with structures such as breather valves, safety valve exhaust ports, boiling gas exhaust ports, and various instrument pipes that connect to the gas phase space.

[0003] In current engineering practices, a limited number of fixed combustible gas detection probes are often deployed in localized areas on the tank top to monitor for combustible gas leaks in the space above the tank. However, during long-term operation, the combustible gas concentration readings on the monitoring system screen often remain at 0%LEL or close to zero, while on-site personnel using portable detectors can detect a certain concentration of combustible gas when inspecting some tank top structures, and can even detect a slight odor.

[0004] It is evident that in actual testing, there may be contradictory phenomena such as zero readings from fixed detection devices but the actual presence of a small amount of flammable volatile gas in the tank top space, making it difficult to reflect the true flammable gas hazard status of the tank top space in a timely and accurate manner. Summary of the Invention

[0005] This application provides a method, system, equipment, and medium for detecting the concentration of combustible gases in cryogenic storage tank areas, which solves the technical problem that fixed detection devices are inaccurate in detecting combustible volatile gases in the tank top space during actual testing.

[0006] In a first aspect, this application provides a method for detecting the concentration of combustible gas in a cryogenic storage tank area, comprising: Combustible gas detection units are deployed in the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy. The combustible gas detection units include point-type combustible gas detection units and area-type combustible gas detection units. The combustible gas detection units are used to detect two different height layers in the tank top monitoring area. Obtain combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period; The combustible gas hazard status of the monitoring area on the top of the tank is determined based on the combustible gas concentration detection data. Based on the flammable gas hazard status, generate flammable gas concentration detection results for the cryogenic storage tank area.

[0007] Secondly, this application provides a combustible gas concentration detection system for cryogenic storage tank areas, comprising: The deployment module is used to deploy combustible gas detection units in the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy. The combustible gas detection units include point-type combustible gas detection units and area-type combustible gas detection units. The combustible gas detection units are used to detect two different height layers in the tank top monitoring area. The acquisition module is used to acquire the combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period; The determination module is used to determine the flammable gas hazard status of the monitoring area on the top of the tank based on the flammable gas concentration detection data; The generation module is used to generate combustible gas concentration detection results for the cryogenic storage tank area based on the combustible gas hazard status.

[0008] Thirdly, this application provides an electronic device, comprising: Processor; and, Memory for storing the executable instructions of the processor; The processor is configured to perform any of the possible methods described in the first aspect by executing the executable instructions.

[0009] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement any of the possible methods described in the first aspect.

[0010] The combustible gas concentration detection method, system, equipment, and medium provided in this application for cryogenic tank area deploy combustible gas detection units based on a preset deployment strategy within the monitoring area on the tank top of the cryogenic tank area. Then, the combustible gas concentration detection data output by the combustible gas detection units within a preset detection period is acquired. Then, the combustible gas hazard status of the tank top monitoring area is determined based on the combustible gas concentration detection data. Finally, the combustible gas concentration detection result of the cryogenic tank area is generated based on the combustible gas hazard status. Through comprehensive monitoring at multiple heights, the coverage capability of cold heavy gas stratification can be improved, so that slowly volatile gases that were originally missed by a few points at a single height can be reliably detected, thereby timely and accurately reflecting the true combustible gas hazard status of the tank top space of the cryogenic tank area. Attached Figure Description

[0011] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0012] Figure 1 This is a schematic flowchart illustrating a method for detecting the concentration of combustible gas in a cryogenic storage tank area according to an example embodiment of this application; Figure 2 yes Figure 2 This is a flowchart illustrating a possible implementation of S110 according to an example embodiment of this application; Figure 3 This is a flowchart illustrating a possible implementation of S110 according to another example embodiment of this application; Figure 4 This is a schematic diagram of the structure of a combustible gas concentration detection system for a cryogenic storage tank area, according to an example embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device according to an example embodiment of this application.

[0013] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0014] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0015] Analysis of the technical problems mentioned above reveals that they primarily stem from a mismatch between the physical properties of the gas and the flow field organization characteristics in the top space of the cryogenic storage tank area, as well as the existing sampling point layout and detection mechanism. First, the flammable vapor escaping from the cryogenic liquefied medium has the characteristics of cold heavy gas with low temperature and high density. Under the influence of ambient heating and surrounding air convection, it is easy to form a significant vertical temperature gradient and density stratification on the surface of the tank top. The leaked gas may form a local stable gas layer at a certain height above the tank top plate or slowly crawl along the surface of the tank top. However, in the existing technology, the probe is often only deployed at a single or limited height, resulting in insufficient spatial coverage.

[0016] Secondly, the tank top has various structures such as ladders, platforms, guardrails, and instrument supports. Under the influence of changing wind direction and speed, small-scale eddies and dead zones are easily formed on its leeward side. A small amount of leaked gas can linger and accumulate in these areas, forming localized high-concentration small gas clouds. The effective response volume of point-type combustible gas detection units is usually limited to a limited range near the probe. If the detection points are not placed close to the above-mentioned key leakage sources and eddy dead zones, it will be difficult to collect representative gas samples in a timely manner.

[0017] To address the aforementioned issues, the embodiments provided in this application target the temperature stratification, density differences, and complex three-dimensional flow field distribution characteristics of combustible gas leakage in the tank top space of cryogenic storage tank areas. By setting at least two layers of point-type combustible gas detection unit rings vertically above the tank top plate of the target storage tank, local concentration collection of gas layers at different heights is formed at a first preset height and a second preset height from the tank top plate, thereby capturing the suspended layer or the flow layer attached to the top that may be formed by the cold heavy gas in the vertical direction.

[0018] Furthermore, near-source combustible gas detection units are deployed around key leak source locations such as safety valve exhaust ports, breather valves, boiling gas exhaust ports, and instrument pipes connected to the gas phase space. This moves the detection volume forward to the high-concentration envelope region of the initial leak plume, reducing signal attenuation caused by diffusion and dilution.

[0019] Furthermore, by deploying open-path combustible gas detection units along a preset monitoring path within the tank top monitoring area, the infrared beam can cross multiple local flow field regions and detect the average concentration along the optical path using a line integration measurement method, thereby spatially compensating for the monitoring gaps between point-type detection units.

[0020] In addition, for vortex dead zones such as under escalators, under platforms, and on the leeward side of tank top structures, extraction sampling heads are installed and connected to a centralized combustible gas analysis unit through sampling pipelines. By using active suction and multi-channel polling analysis, stagnant gas that would not naturally flow to the vicinity of the probe is forcibly introduced into the analysis system for detection.

[0021] Figure 1 This is a schematic flowchart illustrating a method for detecting the concentration of combustible gases in a cryogenic storage tank area, according to an example embodiment of this application. Figure 1 As shown, the method provided in this embodiment includes: S110. Deploy multiple combustible gas detection units in the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy.

[0022] Specifically, multiple types of combustible gas detection units can be deployed within the monitoring area on the top of the cryogenic storage tank area based on a pre-defined deployment strategy. These multiple types of combustible gas detection units include at least one of the following: point-type combustible gas detection units and area-type combustible gas detection units. The combustible gas detection units are used to detect two different height layers within the monitoring area on the top of the tank. Furthermore, when subsequently analyzing the combustible gas concentration results, a single judgment can be made based on one of the multiple types of combustible gas detection units, or a combined judgment can be made based on multiple detection units.

[0023] The aforementioned cryogenic tank area refers to tanks where the stored or transported flammable media are kept at temperatures below 0°C. Optionally, for example, the inspection could be conducted on cryogenic tank storage areas maintained in a temperature range of −165°C to −40°C to keep the flammable media in a liquefied state.

[0024] Figure 2 This is a flowchart illustrating a possible implementation of S110 according to an example embodiment of this application. For example... Figure 2 As shown, the above-mentioned S110 includes: S210. At least two layers of point-type combustible gas detection unit rings shall be installed vertically above the top plate of the target storage tank in the cryogenic storage tank area.

[0025] It is worth noting that in the first operating condition, because the medium inside the tank is at a low temperature, the flammable vapor escaping from the top of the tank is characterized by its coldness, heaviness, and poor fluidity, making it prone to local stratification and accumulation in the tank top space. Specifically, the temperature of the vapor leaking from the cryogenic storage tank is much lower than that of the surrounding ambient air, and its density is relatively high. Under the combined effects of buoyancy and gravity, it easily forms a cold, heavy gas layer within a certain height range above the tank top plate or creeps along the tank top surface, rather than immediately mixing fully with the warm air above. This results in a significant temperature gradient and concentration stratification in the vertical direction of the tank top space. If the probe is only placed at a single height, it may fail to detect the height corresponding to the vapor stratification. This may lead to situations where the monitoring system consistently displays a flammable gas concentration of zero or near zero, while portable detectors or odor sensors can detect a certain concentration of flammable gas in localized areas, resulting in substantial blind spots in safety monitoring and the risk of misjudging safety.

[0026] Therefore, in this step, at least two layers of point-type combustible gas detection unit rings can be set vertically above the top plate of the target tank in the cryogenic tank area, with the at least two layers of point-type combustible gas detection unit rings respectively arranged at a first preset height and a second preset height from the top plate of the tank.

[0027] Among them, each point-type combustible gas detection unit in the above-mentioned point-type combustible gas detection unit circle adopts an industrial infrared combustible gas detector, such as a fixed combustible gas detector.

[0028] For example, at least one of the following can be used: GMI Industrial's GS700 detector, Honeywell Analytics Industrial's Searchline Excel fixed infrared combustible gas detector, and MSA Industrial's Ultima XIR fixed infrared combustible gas detector. A specific model suitable for ambient temperatures of -40°C and below should be selected to ensure long-term reliable operation above the tank top plate in the cryogenic storage tank area.

[0029] Specifically, a number of support components for installing point-type combustible gas detection units can be installed circumferentially on the outer side of the outer edge of the top plate of the target storage tank. The support components include support poles fixed to the top plate or the top railing posts and circumferential support beams fixedly connected to the support poles.

[0030] Then, mounting bases are set at the first and second preset heights from the top plate of the tank along the height direction of the support pole. The mounting bases are used to fix the point-type combustible gas detection unit at the corresponding height position.

[0031] At a first preset height from the top plate of the tank, several first point-type combustible gas detection units are fixed sequentially at a first preset angle interval along the circumferential support beam, so that the probes of the first point-type combustible gas detection units face the center of the top plate of the tank or the plane on the surface of the top plate of the tank, thereby forming a first layer of point-type combustible gas detection unit ring.

[0032] At a second preset height from the top plate of the tank, several second point-type combustible gas detection units are fixed sequentially along the circumferential support beam at second preset angle intervals. The second preset angle interval may be the same as or different from the first preset angle interval. The second point-type combustible gas detection units are staggered with the adjacent first point-type combustible gas detection units in the plane projection direction, thereby forming a second layer of point-type combustible gas detection unit ring.

[0033] In addition, both the first and second layer of point-type combustible gas detection unit circles form a basically closed ring arrangement around the projected outer edge of the tank top plate, and the circumferential spacing between adjacent point-type combustible gas detection units is less than or equal to a preset circumferential spacing threshold, so as to ensure continuous monitoring coverage of combustible gas leakage around the tank top plate.

[0034] Optionally, the first preset height can be configured to be 0.2m to 0.5m from the top of the tank, and the second preset height can be configured to be 0.8m to 1.5m from the top of the tank. It is worth noting that in this embodiment, the specific installation and fixing position of the point-type combustible gas detection unit ring is not specifically limited. In order to achieve this technical objective, it is only necessary to ensure that the detection height is within the corresponding height range.

[0035] It is worth noting that the specific basis for configuring the first preset height to be 0.2m to 0.5m from the top of the tank is as follows: Considering that when a flammable medium leaks from a cryogenic storage tank, the leaked gas, due to its low temperature and higher density than the surrounding air, initially forms a layer of highly concentrated flammable gas along the surface of the tank top plate and near the tank top structure, and the characteristic thickness of this layer of highly concentrated flammable gas is usually above 0.1m.

[0036] To avoid the risks of rainwater accumulation, snow cover, and mechanical collision caused by directly placing the point-type combustible gas detection unit close to the surface of the tank top plate, and to ensure that the detection volume of the point-type combustible gas detection unit is still within the dominant thickness range of the high-concentration combustible gas layer, the first preset height is limited to 0.2m to 0.5m from the tank top plate.

[0037] When the first preset height is less than 0.2m, the probe of the point-type combustible gas detection unit is easily affected by factors such as ice formation, water accumulation on the tank top surface, and trampling by operating personnel, leading to probe blockage or measurement distortion. When the first preset height is greater than 0.5m, under stable weather conditions or light wind conditions, high-density combustible gas may be confined to the boundary layer closer to the tank top, resulting in reduced response sensitivity of the point-type combustible gas detection unit or the appearance of monitoring blind spots. Therefore, by limiting the first preset height to the range of 0.2m to 0.5m, priority interception and effective monitoring of combustible gas leak plumes attached to the vicinity of the tank top can be achieved.

[0038] The specific basis for configuring the second preset height to be 0.8m to 1.5m from the top of the tank is as follows: After a low-temperature flammable gas leaks, over time and due to the influence of the surrounding wind field, some of the low-temperature gas is entrained, diluted, and lifted by the surrounding air, forming a thick turbulent mixing layer above the tank top plate. The dominant thickness of this mixing layer typically extends to a spatial height of about 1.0m to 2.0m above the tank top plate.

[0039] In order to enable the second layer of point-type combustible gas detection unit rings to intercept combustible gas clouds that have undergone a certain height rise and dilution, and to form complementary coverage with the first layer of point-type combustible gas detection unit rings in the vertical direction, the second preset height is limited to 0.8m to 1.5m from the top plate of the tank.

[0040] When the second preset height is less than 0.8m, the vertical height difference between the second-layer point-type combustible gas detection unit and the first-layer point-type combustible gas detection unit is insufficient, which easily leads to the overlap of the monitoring volumes of the two detection rings, weakening the ability to distinguish the stratification of the vertical diffusion process of combustible gas. When the second preset height is greater than 1.5m, under common stable or neutral atmospheric stratification conditions, the low-temperature combustible gas cloud may not have risen sufficiently to this height, resulting in a reduced effective triggering probability of the second-layer point-type combustible gas detection unit. Therefore, by limiting the second preset height to the range of 0.8m to 1.5m, multi-layer monitoring and trend identification of combustible gas in the rising and diffusion stages can be achieved.

[0041] The above-mentioned S210 is based on the cold heavy gas stratification mechanism. By deploying point probe rings at a first preset height (e.g., 0.2m to 0.5m) near the top plate of the tank and at a second preset height (e.g., 0.8m to 1.5m) above it, the cold heavy gas layer formed under different wind speeds and ambient temperatures and its upper mixing layer have corresponding detection cross sections, which geometrically increases the overlap probability of the leakage cloud and the effective detection volume of the probe.

[0042] S220. Deploy near-source combustible gas detection units around the critical leak source location on the top of the target storage tank.

[0043] It is worth noting that in the second operating condition, the existing structures on the tank top create a complex three-dimensional flow field under the influence of the incoming airflow. This generates low-speed eddies or ventilation dead zones in areas such as under the escalator, under the platform, and on the leeward side, causing trace amounts of leaked gas to linger in these local spaces for extended periods. This results in small localized clusters of gas with higher concentrations than the surrounding background. The horizontal and vertical positions of these clusters often deviate from the positions of traditional point probes, which are roughly evenly distributed along passageways, railings, or equipment. Furthermore, the effective detection volume of point probes is usually limited to a finite distance around the probe, and there is a certain delay in response time and system sampling cycle. When the leak cloud sweeps past at a certain speed or exists for a short time at the edge of the probe's detection volume, the probe output is easily averaged to a low or zero value, further amplifying the monitoring blind zone.

[0044] In this step, a near-source combustible gas detection unit may be deployed around the critical leak source location on the top of the target storage tank. The critical leak source location includes at least one of the following: safety valve exhaust port, breather valve, boiling gas exhaust port, and instrument piping connected to the gas phase space.

[0045] Among them, the aforementioned near-source combustible gas detection unit can be a fast-response catalytic combustion combustible gas detector, such as a fixed catalytic combustion combustible gas detector.

[0046] For example, it could be at least one of the following: Hansoh Technology HS-CAT200 fixed catalytic combustion combustible gas detector, MSA PrimaX I fixed catalytic combustion combustible gas detector, or Honeywell Industrial Sensepoint XCDCombustible fixed catalytic combustion combustible gas detector. Preferably, a specific model suitable for Zone 0 or Zone 1 explosive gas environments with a temperature group of T4 or higher should be selected to ensure continuous online safe operation of the near-source combustible gas detection unit in high-risk areas of critical leak sources.

[0047] Optionally, the horizontal distance between the aforementioned near-source combustible gas detection unit and the corresponding critical leak source location is configured to be less than or equal to 0.5m. It is worth noting that in this embodiment, the specific installation method of the near-source combustible gas detection unit is not specifically limited. In this embodiment, to achieve the technical objective, it is only necessary to ensure that its detection height is within the corresponding height range. The specific basis for its height setting is as follows: Considering that the key leakage sources include the safety valve exhaust port, breather valve, boiling gas discharge port, and instrument pipes connected to the gas phase space, under the conditions of opening or failure, the combustible medium is ejected from the vent at a certain flow rate and momentum, and a high-concentration, narrow jet or plume type initial diffusion zone is first formed in the vicinity of the vent. The high-concentration characteristic range of this initial diffusion zone is mainly concentrated within 0.5m of the vent.

[0048] To improve the response speed to early leaks of small flow rates and intermittent venting conditions, and to reduce the near-source monitoring blind zone caused by the deviation of high-concentration jets due to instantaneous changes in wind direction, the horizontal distance between the near-source point-type combustible gas detection unit and the corresponding key leak source location is limited to less than or equal to 0.5m.

[0049] When the horizontal distance is greater than 0.5m, under conditions of high wind speed or strong turbulence, the leaked gas will be significantly diluted and lifted before reaching the location of the point-type combustible gas detection unit. The high-concentration area may bypass the detection location, causing delayed response or missed detection of short-term high-risk leaks. However, when the horizontal distance is controlled at 0.5m or less, the detection volume of the point-type combustible gas detection unit can stably fall within the high-concentration envelope of the initial leak plume, thus ensuring the near-source rapid detection capability of critical leak sources.

[0050] For the aforementioned S220, targeting localized eddy dead zones and near-source high-concentration clusters, point probes are deployed around the safety valve exhaust port, breather valve, boiling gas exhaust port, and instrument connecting pipes connected to the gas phase space, with the horizontal distance controlled within a certain range. This allows the probes to directly sample the high-concentration core area of ​​the leaking plume in the early stages of diffusion, thus mitigating the impact of macroscopic flow field uncertainties on the detection results.

[0051] S230. At least one open optical path combustible gas detection unit is deployed along a preset monitoring path within the monitoring area on the top of the tank to detect the linear integral concentration of combustible gas passing through the optical path.

[0052] Optionally, the aforementioned open-path combustible gas detection unit can be an open-path infrared combustible gas detector, such as at least one of the Honeywell Analytics Industrial Searchline Excel open-path infrared combustible gas detector or the CSIC-OLIR open-path infrared combustible gas detector from China Shipbuilding Industry Corporation. Preferably, a specific model meeting the requirements of an optical path range of not less than 5m and not more than 200m, and an operating ambient temperature suitable for -40℃ to +60℃, should be selected to ensure reliable optical alignment and long-term stable operation of the open-path combustible gas detection unit in the complex wind field environment on the tank top of cryogenic storage tank areas. It is worth noting that the aforementioned open-path combustible gas detection unit is a zone-type combustible gas detection unit.

[0053] In one possible implementation, at least one closed or segmented closed open optical path can be provided circumferentially around the periphery of the safety valve discharge area.

[0054] Specifically, several supporting columns can be installed circumferentially around the target storage tank outside the safety valve discharge area. These columns are fixed to the tank top plate or tank top platform structure and are used to support the transmitter and receiver of the open-path combustible gas detection unit. Then, the transmitter and receiver of the open-path combustible gas detection unit are fixed circumferentially between two adjacent supporting columns using mounting brackets, so that the detection beam emitted by the transmitter forms an open optical path within the effective receiving range of the receiver.

[0055] Next, multiple adjacent open optical paths can be connected end to end to form a closed open optical path around the safety valve emission area, or at least two segmented closed open optical paths with end-to-end spacing can be formed within a local circumferential range of the emission area.

[0056] The optical axis height of each open optical path is set to be higher than the preset optical path height of the tank top plate, so that the open optical path passes through the main diffusion space of the expected combustible gas plume around the safety valve discharge area, so as to perform linear integral concentration detection of combustible gas in the diffusion space.

[0057] In another possible implementation, at least one radially open optical path can be provided between the center of the top of the target storage tank and the edge of the top of the tank.

[0058] Specifically, a first mounting base may be set at a position near the center of the top of the target storage tank, and multiple second mounting bases may be set at several positions around the circumference near the edge of the top of the tank. Both the first and second mounting bases are fixed to the structural components of the top plate or the top platform of the tank.

[0059] Then, the transmitting unit and receiving unit of the open optical path combustible gas detection unit are arranged radially between the first mounting base and each of the second mounting bases, so that the optical axes of the transmitting unit and the receiving unit are aligned in the radial direction from the center of the tank top to the edge of the tank top, thereby forming at least one radial open optical path in each radial direction.

[0060] The optical axis height of the radial open optical path is then set to be higher than the preset optical path height of the tank top plate, and the preset optical path height is the same as or different from the preset optical path height of the central circumferential open optical path, so that the radial open optical path and the circumferential open optical path form a monitoring network that crosses and covers each other in space.

[0061] Furthermore, by adjusting the distribution angle of the second mounting base in the circumferential direction, the included angle between two adjacent radial open optical paths in the plane projection direction is less than or equal to the preset maximum radial included angle threshold, so as to ensure coverage of different radial leakage diffusion paths in the monitoring area on the top of the tank.

[0062] It is worth noting that in this embodiment, the specific installation method of the open optical path combustible gas detection unit is not specifically limited. In order to achieve the technical objective in this embodiment, it is only necessary to ensure that it can detect the required coverage area.

[0063] For the S230 mentioned above, the open optical path combustible gas detection unit is based on the spectral absorption principle that the light intensity is attenuated due to the absorption of specific wavelength infrared light by combustible component molecules. By arranging an optical path of a certain length along the circumferential or radial direction in the key area of ​​the tank top, the unit can achieve the integral measurement of gas concentration along the optical path direction. Even if the local concentration cloud only occupies a small part of the optical path, its absorption of the total optical path will still produce a measurable change, thereby intercepting and detecting the leak cloud in a line rather than a point manner.

[0064] In summary, for S210-S230, firstly, by setting at least two layers of point-type combustible gas detection unit rings vertically within the monitoring area on the top of the cryogenic storage tank area, and implementing near-source point deployment around key leak source locations, while simultaneously configuring open optical path combustible gas detection units along the preset monitoring path, the linear integral concentration detection of combustible gas passing through the optical path is performed, effectively improving the coverage and detection capability of the tank top space for small amounts of volatile or small leaking combustible gas clouds. Specifically, the multi-height point-type detection unit rings can cover different typical layer heights above the tank top plate, effectively intercepting cold heavy gas layers that may form under different temperature and wind conditions.

[0065] Secondly, the near-source detection unit is closely attached to the leakage sources such as the safety valve exhaust port, breather valve, boiling gas exhaust port, and instrument pipes connected to the gas phase space, which can achieve early local high concentration detection before the combustible gas has spread over a large area.

[0066] Furthermore, the open optical path detection units deployed along the circumferential and radial directions perform surface-scanning monitoring of combustible gas clouds crossing the optical path using line integration. Even if the gas cloud only forms briefly in a narrow area at the top of the tank, it can be identified as a whole within the length covered by the optical path.

[0067] By combining various types, heights, and near-source / regional locations, the tank top combustible gas monitoring system can upgrade the original point monitoring that relied on only a few single-point sensors to a three-dimensional monitoring mode that combines point detection and line detection. This effectively reduces missed detections caused by stratification, eddy dead zones, and short-term passage of gas clouds, enabling early and reliable identification of combustible gas hazards in scenarios with minor leaks or volatilization at the top of cryogenic storage tanks.

[0068] also, Figure 3 This is a flowchart illustrating a possible implementation of S110 according to another example embodiment of this application. For example... Figure 3 As shown, the above-mentioned S110 includes: S310. Install extraction sampling heads in the eddy current dead zone area within the monitoring area on the top of the tank.

[0069] Optionally, an extraction sampling head can be installed in the eddy dead zone area of ​​the tank top monitoring area. The eddy dead zone area includes at least one of the following: below the escalator, below the platform, and the leeward side area of ​​the tank top structure.

[0070] Optionally, at least one extraction sampling head can be installed at first preset horizontal intervals along the projection direction of the escalator below it, preferably 1.5m to 3m, to ensure full coverage of the passageway below the escalator. At least two extraction sampling heads can be installed along the edge of the platform below it, with the horizontal distance between any two adjacent extraction sampling heads being less than or equal to a second preset horizontal interval, preferably 2m. In the leeward side area of ​​the tank top structure, at least one extraction sampling head can be installed along the leeward edge of the prevailing wind direction of the device, preferably at a vertical installation height of 0.2m to 1.0m from the tank top plate, so that the sampling port of the extraction sampling head is located in the near-plate layer where combustible gases are easily retained.

[0071] The aforementioned extraction sampling head can be an explosion-proof stainless steel gas sampling probe suitable for online analysis of combustible gases, such as at least one of the GSP-300 series extraction gas sampling probes manufactured by GASTRON, the SITRANS SAM sampling probe manufactured by SIEMENS, or equivalent explosion-proof extraction gas sampling probes.

[0072] Specifically, a filter assembly inside the extraction sampling head can be used to perform primary particulate filtration on the gas entering the sampling pipeline, preventing droplets, ice crystals, and solid particles from entering the sampling pipeline and the centralized combustible gas analysis unit. Furthermore, a pump used in conjunction with the extraction sampling head establishes a stable negative or slightly positive pressure airflow field within the sampling pipeline, allowing surrounding gas in the vortex dead zone area to be continuously or intermittently drawn into the centralized combustible gas analysis unit at a preset flow rate.

[0073] Then, based on negative pressure drive and preset flow rate, the combustible gas that is locally stagnant on the leeward side of the tank top structure, below the platform and below the escalator is disrupted from its original local vortex equilibrium state and migrates directionally along the sampling pipeline, thereby realizing the active extraction of gas components in the dead zone area of ​​the tank top vortex.

[0074] S320. The extraction sampling head is connected to the centralized combustible gas analysis unit located in the analysis cabinet near the storage tank through the sampling pipeline.

[0075] Specifically, sampling pipelines made of stainless steel or low-temperature alloy can be used to connect each extraction sampling head to the switching valve manifold located inside the analysis cabinet. The inner diameter of the sampling pipeline is preferably 4mm to 10mm to reduce pipeline pressure drop while ensuring response speed.

[0076] Optionally, an insulation layer and heating elements can be installed outside the sampling pipeline to maintain the temperature of the sampled gas above 0°C to prevent condensation and freezing. Furthermore, the centralized combustible gas analysis unit is housed in an analysis cabinet with insulation and heating functions, maintaining the ambient temperature within the analysis cabinet within a first temperature range. The analysis cabinet contains the sample inlet of the centralized combustible gas analysis unit, and multiple sampling pipelines are sequentially connected to the unified sample inlet of the centralized combustible gas analysis unit according to their channel numbers via a switching valve.

[0077] S330: The centralized combustible gas analysis unit controls the sampling channels of multiple sampling heads to switch sequentially within a preset sampling period, and performs polling analysis on the combustible gas concentration of each sampling channel.

[0078] In this step, the number of sampling channels N and the total sampling period T can be set, and the effective sampling time Δt of a single channel can be determined based on N and T, such that T≈N×Δt. Then, at the beginning of each sampling period T, the switching valve is controlled to the sampling channel corresponding to the first extraction sampling head, and the sampling pipeline is purged with a preset flow rate within a preset purging time t1, wherein t1 is preferably 10s to 60s, to replace the residual gas in the previous channel.

[0079] After purging is completed, the sampling channel is kept connected within the single-channel effective sampling time Δt, and the combustible gas concentration data and corresponding timestamps output by the centralized combustible gas analysis unit are collected and recorded.

[0080] After the effective sampling time Δt of each single channel ends, the switching valve is switched to the sampling channel corresponding to the next numbered extraction sampling head, until the polling analysis of all N sampling channels is completed in sequence.

[0081] For the above S310-S330, the extraction sampling head installed in the vortex dead zone area on the top of the tank forms a closed air extraction channel with the centralized combustible gas analysis unit through the sampling pipeline. Within the preset sampling period, the air extraction pump or negative pressure device establishes a stable small flow rate continuous airflow in each sampling channel, so that the air inside the vortex dead zone is actively extracted to the analysis unit.

[0082] Furthermore, the centralized combustible gas analysis unit preferably adopts a high-precision detection principle based on infrared absorption, catalytic combustion, or other suitable stable environmental conditions. It connects to different sampling channels in sequence through switching valves to perform quantitative analysis on the sample gas sent into each channel.

[0083] Because the ambient temperature inside the analysis cabinet can be maintained within a set range through insulation and heating, combined with the insulation and heat tracing of the sampling pipeline, the extracted gas does not undergo significant condensation or compositional changes during transmission and detection. This ensures that the measured combustible gas concentration accurately reflects the true gas conditions in the vortex dead zone area where the extraction point is located. Through time-multiplexed multi-channel sampling and centralized high-sensitivity measurement, active sampling and effective monitoring of local spaces in complex three-dimensional flow fields where gas is difficult to reach point probes can be achieved without significantly increasing the number of on-site explosion-proof detection devices on the tank top. This solves the technical problem of fixed point probes having zero readings but actually containing a small amount of volatile gas.

[0084] S120. Obtain combustible gas concentration detection data output by multiple combustible gas detection units within a preset detection period.

[0085] In the above Figure 2 In a possible implementation of the illustrated embodiment, this step may involve obtaining the instantaneous concentration or lower explosive limit percentage output by each point-type combustible gas detection unit, and obtaining the average concentration or lower explosive limit along the optical path output by each open optical path combustible gas detection unit. Then, the various combustible gas concentration detection data are time-synchronized based on the timestamp.

[0086] In the above Figure 3In a possible implementation of the illustrated embodiment, this step may involve obtaining the combustible gas concentration output by the centralized combustible gas analysis unit for each extraction sampling channel. If the combustible gas concentration is higher than a preset concentration threshold, the monitoring area on the top of the tank is determined to be in an alarm state.

[0087] S130. Determine the flammable gas hazard status of the monitoring area on the top of the tank based on the flammable gas concentration detection data.

[0088] In this step, the flammable gas hazard status of the tank top monitoring area can be determined based on the data from various flammable gas detection units. For example, the presence of a flammable gas hazard can be determined by comparing the data from various flammable gas detection units with corresponding thresholds and by analyzing the rate of change of the data from each unit.

[0089] Furthermore, it is also possible to fuse and determine the combustible gas concentration detection data, and to ascertain the combustible gas hazard status of the tank top monitoring area based on multi-point spatial correlation and temporal trends. Specifically, this can involve weighted fusion of detection data from different types of combustible gas detection units within the same tank top monitoring area to obtain a fused concentration index. Then, time series analysis is performed on the fused concentration index, and the tank top monitoring area is classified into at least one of the following states: normal state, warning state, and alarm state.

[0090] Specifically, each point-type combustible gas detection unit and each open optical path combustible gas detection unit deployed in the same tank top monitoring area can be divided into several monitoring sub-areas, and corresponding point-type weight coefficients and open optical path weight coefficients can be pre-configured for each monitoring sub-area.

[0091] Next, within each preset detection cycle, the instantaneous concentration or lower explosive limit percentage output by each point-type combustible gas detection unit belonging to the same monitoring sub-region is weighted and summed to obtain the first type of sub-fusion concentration. The average concentration or lower explosive limit output along the optical path of each open optical path combustible gas detection unit belonging to the same monitoring sub-region is weighted and summed to obtain the second type of sub-fusion concentration.

[0092] Then, based on the spatial location and airflow organization characteristics of the monitoring sub-region in the tank top monitoring area, the first type of sub-fusion concentration and the second type of sub-fusion concentration are subjected to secondary weighting to obtain the target fusion concentration value of the corresponding monitoring sub-region.

[0093] Furthermore, the target fusion concentration values ​​of all monitoring sub-regions are aggregated according to the preset spatial coverage weight to obtain the fusion concentration index for the tank top monitoring area, which is used for subsequent time series analysis and flammable gas hazard status determination.

[0094] The determination of the weighting coefficients for the aforementioned weighted fusion can be achieved by using the horizontal distance and height difference between each point-type combustible gas detection unit and the location of the critical leak source, and determining the corresponding point-type weighting coefficient according to the inverse distance principle or a piecewise distance function, so that point-type combustible gas detection units closer to the critical leak source receive higher weights. Similarly, the weighting coefficients for open optical path combustible gas detection units can be determined based on the overlap area or volume between the optical path coverage of each unit and the tank top monitoring area, so that open optical path combustible gas detection units with larger coverage areas or those traversing critical leak paths receive higher weights. Finally, all weighting coefficients are normalized so that the sum of the weighting coefficients of each point-type combustible gas detection unit and each open optical path combustible gas detection unit within the same monitoring sub-region is 1, thereby ensuring that the physical dimensions of the fused concentration index remain consistent with the original concentration.

[0095] Furthermore, for the aforementioned time series analysis of the fusion concentration index, the first derivative of the fusion concentration index can be calculated within a preset time window to determine the rate of concentration change. The moving average of the fusion concentration index can also be calculated within the preset time window to smooth out transient disturbances.

[0096] When the moving average is below the first concentration threshold but the first derivative remains positive for a duration exceeding the first time threshold, the monitoring area on the top of the tank is identified as being in an early warning state.

[0097] When the fusion concentration index exceeds the second concentration threshold or the linear integral concentration of the open optical path combustible gas detection unit exceeds the third concentration threshold, the monitoring area on the top of the tank will be set to an alarm state.

[0098] Furthermore, it is worth mentioning that, under actual working conditions, for Figure 2 In the illustrated embodiment, the cold heavy gas plume near the tank top is not only affected by gravity and buoyancy, but also by transient wind fields, such as gusts, sudden changes in wind direction, and vertical wind shear. This causes the concentration distribution of the leaked gas plume at different altitudes to exhibit significant time-varying characteristics. Under these complex flow field conditions, it is impossible to distinguish between normal diffusion and wind-induced lift, which can easily lead to misjudgment of the actual dangerous situation when the cold heavy gas plume is lifted by the wind, posing a potential safety hazard.

[0099] In the monitoring area on the top of the cryogenic storage tank, when the concentration distribution of the cold heavy gas plume is reconstructed under the influence of short-term strong winds or wind field disturbances, resulting in a transient concentration reversal between the upper and lower point-type combustible gas detection units, it is necessary to further address how to identify whether this concentration reversal is a wind-induced cold heavy gas rise or redistribution process, rather than the end of the leak or the elimination of the risk. This is to avoid prematurely reverting the tank top monitoring area, which is in a warning or alarm state, to a normal state, thereby improving the accuracy of identifying continuous leakage hazards under complex wind field conditions.

[0100] To address this, the instantaneous concentration or lower explosive limit percentage of the upper and lower point-type combustible gas detection units deployed at different heights within the tank top monitoring area can be obtained respectively. The first concentration difference at each sampling moment can be calculated, obtained by subtracting the instantaneous concentration of the lower point-type combustible gas detection unit from the instantaneous concentration of the upper unit. Then, within a preset first time window, the concentration change rate of the upper and lower point-type combustible gas detection units is calculated to obtain the upper and lower concentration change rates. Specifically, if the time it takes for the first concentration difference to cross from negative to zero and remain positive within the preset first time window is not less than a first duration threshold, and the upper concentration change rate is greater than a first change rate threshold and the lower concentration change rate is less than or equal to a second change rate threshold within the preset first time window, the tank top monitoring area at the current moment is marked as a concentration reversal candidate event, thus preventing the tank top monitoring area from directly reverting from a warning or alarm state to a normal state.

[0101] In the above steps, starting from the time series characteristics of the monitoring data, the spatial distribution evolution of the cold heavy gas plume in the vertical direction is transformed into a combination pattern of concentration difference sign change and rate of change that can be recognized by the algorithm.

[0102] Specifically, firstly, by obtaining the corresponding instantaneous concentration or lower explosive limit percentage of the upper and lower point combustible gas detection units deployed at two different heights, the first concentration difference is calculated at each sampling time to reflect the instantaneous gradient relationship between the upper and lower layers.

[0103] Secondly, within the preset first time window, the concentration change rate of the upper-layer point-type combustible gas detection unit and the lower-layer point-type combustible gas detection unit are calculated respectively to obtain the upper-layer concentration change rate and the lower-layer concentration change rate, thereby depicting the local increase and decrease trend of the cold heavy gas plume at the two height layers.

[0104] Furthermore, by constraining the time for the first concentration difference to cross from negative to zero and remain positive within the time window to be no less than the first duration threshold, and simultaneously requiring the upper layer concentration change rate to be greater than the first change rate threshold and the lower layer concentration change rate to be less than or equal to the second change rate threshold, the wind-induced uplift pattern of rapid increase in upper layer concentration, decrease in lower layer concentration instead of increase, and continuous reversal of gradient is achieved.

[0105] Finally, the time periods that meet the combined criteria are marked as concentration reversal candidate events, and the state machine logic prohibits the direct reversion of the tank top monitoring area from the warning state or alarm state to the normal state during such events. This enables the monitoring system to reliably identify and prevent false reversal of wind-induced reversal leakage scenarios based on the dynamic relationship between upper and lower layer monitoring data without directly analyzing the transient flow field.

[0106] Furthermore, horizontal wind speed, horizontal wind direction, and wind speed data at different heights, synchronized with a preset detection cycle, can be obtained from meteorological monitoring units deployed in the cryogenic storage tank area. Within a preset second time window, the rate of change of horizontal wind speed, the change of horizontal wind direction, and the vertical wind shear index based on wind speed data at different heights are calculated. When the horizontal wind speed exceeds a preset strong wind threshold and / or the absolute value of the rate of change of wind speed exceeds a preset rate of change threshold and / or the vertical wind shear index exceeds a preset wind shear threshold within the preset second time window, the wind field state for the corresponding time period is marked as a strong disturbance wind field with the potential for cold heavy air lifting.

[0107] Then, within the time period when a concentration reversal candidate event is detected, it is determined whether a strong disturbance wind field with the potential for cold heavy gas to rise exists simultaneously, and whether the instantaneous concentration or moving average concentration of the upper-layer point-type combustible gas detection unit or the lower-layer point-type combustible gas detection unit reaches a preset proportion of the preset warning concentration threshold within the preset third time window.

[0108] If the above conditions are met simultaneously, the current flammable gas hazard status of the tank top monitoring area will be determined as a continuous leakage scenario under wind-induced reversal, and it will be prohibited to directly revert the status of the tank top monitoring area from the warning status or alarm status to the normal status within the preset observation delay window, thereby further improving the accuracy of the monitoring status and improving the accurate identification and reliable control of leakage hazard status under strong disturbance wind fields.

[0109] S140. Generate combustible gas concentration detection results for the cryogenic storage tank area based on the combustible gas hazard status.

[0110] In this step, the flammable gas hazard status of the tank top monitoring area can be mapped to the preset alarm classification rules, with the normal status corresponding to the level zero alarm, the warning status corresponding to the level one alarm, and the alarm status corresponding to the level two alarm or higher.

[0111] Within each preset detection cycle, based on the current combustible gas hazard status of the tank top monitoring area, a detection result data record is generated, including timestamp, hazard status level, fusion concentration index, line integral concentration of open optical path combustible gas detection unit, and concentration of key point combustible gas detection unit, and the detection result data record is stored in the historical database.

[0112] When the tank top monitoring area is in a normal state, the combustible gas concentration detection result under normal operating conditions is generated, and the status of the tank top monitoring area is marked on the monitoring interface in green or other normal state display mode. At the same time, a continuous trend curve is retained for operators to view.

[0113] When the monitoring area on the top of the tank is in an early warning state, the detection result of the combustible gas concentration in the early warning state is generated. The monitoring area on the top of the tank is highlighted on the monitoring interface in the form of an early warning state display, and an audible and visual early warning prompt is triggered, as well as a remote communication message carrying the early warning information is sent to remind the operators to strengthen on-site inspections and operating condition verification.

[0114] When the monitoring area on the top of the tank is in an alarm state, the detection result of the combustible gas concentration in the alarm state is generated. The monitoring area on the top of the tank is prominently marked on the monitoring interface in the form of an alarm state display. An alarm signal is output to drive the on-site audible and visual alarm, interlocking system or emergency shut-off system, so as to execute safety protection measures such as emergency discharge, shut-off or shutdown according to the process settings.

[0115] In this embodiment, combustible gas detection units are deployed in the monitoring area on the top of the cryogenic storage tank area based on a preset deployment strategy. Then, the combustible gas concentration detection data output by the combustible gas detection units within a preset detection period is acquired. Then, the combustible gas hazard status of the monitoring area on the top of the tank is determined based on the combustible gas concentration detection data. Finally, the combustible gas concentration detection result of the cryogenic storage tank area is generated based on the combustible gas hazard status. Through comprehensive monitoring at multiple heights, the coverage capability of the stratification of cold and heavy gas can be improved, so that slowly volatile gases that were originally missed by a few points at a single height can be reliably detected, thereby reflecting the real combustible gas hazard status of the tank top space of the cryogenic storage tank area in a timely and accurate manner.

[0116] Figure 4 This is a schematic diagram of a combustible gas concentration detection system for a cryogenic storage tank area, according to an example embodiment of this application. Figure 4 As shown, the combustible gas concentration detection system 400 for cryogenic storage tank areas provided in this embodiment includes: The deployment module 410 is used to deploy combustible gas detection units in the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy. The combustible gas detection units include point-type combustible gas detection units and area-type combustible gas detection units. The combustible gas detection units are used to detect two different height layers in the tank top monitoring area. The acquisition module 420 is used to acquire the combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period; The determination module 430 is used to determine the flammable gas hazard status of the monitoring area on the top of the tank based on the flammable gas concentration detection data. The generation module 440 is used to generate a combustible gas concentration detection result for the cryogenic storage tank area based on the combustible gas hazard status.

[0117] Figure 5 This is a schematic diagram of the structure of an electronic device according to an example embodiment of this application. For example... Figure 5 As shown, the electronic device 500 provided in this embodiment includes: a processor 501 and a memory 502; wherein: Memory 502 is used to store computer programs, and the memory may also be flash memory.

[0118] Processor 501 is used to execute the execution instructions stored in the memory to implement the various steps in the above method. For details, please refer to the relevant descriptions in the preceding method embodiments.

[0119] Alternatively, the memory 502 can be either standalone or integrated with the processor 501.

[0120] When the memory 502 is a device independent of the processor 501, the electronic device 500 may further include: Bus 503 is used to connect the memory 502 and the processor 501.

[0121] This embodiment also provides a readable storage medium storing a computer program, which, when executed by at least one processor of an electronic device, enables the electronic device to perform the methods provided in the various embodiments described above.

[0122] This embodiment also provides a program product including a computer program stored in a readable storage medium. At least one processor of an electronic device can read the computer program from the readable storage medium, and the at least one processor executes the computer program to cause the electronic device to perform the methods provided in the various embodiments described above.

[0123] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0124] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for detecting the concentration of combustible gas in a cryogenic storage tank area, characterized in that, include: Combustible gas detection units are deployed in the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy. The combustible gas detection units include point-type combustible gas detection units and area-type combustible gas detection units. The combustible gas detection units are used to detect two different height layers in the tank top monitoring area. Obtain combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period; The combustible gas hazard status of the monitoring area on the top of the tank is determined based on the combustible gas concentration detection data. Based on the flammable gas hazard status, generate flammable gas concentration detection results for the cryogenic storage tank area.

2. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 1, characterized in that, The deployment of combustible gas detection units within the monitoring area on the top of the cryogenic storage tank area, based on a preset deployment strategy, includes: At least two layers of point-type combustible gas detection unit rings are installed vertically above the top plate of the target storage tank in the cryogenic storage tank area. The at least two layers of point-type combustible gas detection unit rings are respectively arranged at a first preset height and a second preset height from the top plate of the tank.

3. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 2, characterized in that, The deployment of combustible gas detection units within the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy also includes: Near-source combustible gas detection units are deployed around the critical leak source locations on the top of the target storage tank. The critical leak source locations include at least one of the following: safety valve exhaust port, breather valve, boiling gas exhaust port, and instrument pipe connected to the gas phase space.

4. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 2 or 3, characterized in that, The deployment of combustible gas detection units within the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy also includes: At least one open optical path combustible gas detection unit is deployed along a preset monitoring path within the monitoring area on the top of the tank to detect the linear integral concentration of combustible gas passing through the optical path.

5. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 2, characterized in that, The first preset height is 0.2m to 0.5m from the top plate of the tank, and the second preset height is 0.8m to 1.5m from the top plate of the tank.

6. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 3, characterized in that, The horizontal distance between the near-source combustible gas detection unit and the corresponding critical leak source location is less than or equal to 0.5m.

7. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 4, characterized in that, The method of deploying at least one open optical path combustible gas detection unit along a preset monitoring path within the monitoring area on the tank top includes: At least one closed or segmented closed open optical path is provided circumferentially around the perimeter of the safety valve discharge area; and / or At least one radially open optical path is provided between the center of the top of the target storage tank and the edge of the top of the tank.

8. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 1, characterized in that, The step of acquiring the combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period includes: Obtain the instantaneous concentration or lower explosive limit percentage output by each point-type combustible gas detection unit; Obtain the average concentration or lower explosive limit along the optical path output of each open optical path combustible gas detection unit; Time synchronization processing is performed on various combustible gas concentration detection data based on timestamps.

9. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 1, characterized in that, Determining the flammable gas hazard status of the tank top monitoring area based on the flammable gas concentration detection data includes: The detection data of different types of combustible gas detection units in the same tank top monitoring area are weighted and fused to obtain the fused concentration index; Time series analysis was performed on the fusion concentration index, and the monitoring area on the top of the tank was divided into at least one of the following states: normal state, early warning state, and alarm state.

10. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 9, characterized in that, The time series analysis of the fusion concentration index includes: The first derivative of the fusion concentration index is calculated within a preset time window to determine the rate of concentration change. The moving average value of the fusion concentration index is calculated within the preset time window to smooth out instantaneous interference; When the sliding average value is lower than the first concentration threshold but the first derivative remains positive for a duration exceeding the first time threshold, the monitoring area on the top of the tank is determined to be in an early warning state. When the fusion concentration index exceeds the second concentration threshold or the linear integral concentration of the open optical path combustible gas detection unit exceeds the third concentration threshold, the tank top monitoring area will be determined to be in an alarm state.

11. The method for detecting combustible gas concentration in a cryogenic storage tank area according to claim 1, characterized in that, The deployment of combustible gas detection units within the monitoring area on the top of the cryogenic storage tank area, based on a preset deployment strategy, includes: An extraction sampling head is installed in the eddy dead zone area of ​​the monitoring area on the top of the tank. The eddy dead zone area includes at least one of the areas below the escalator, below the platform, and the leeward side area of ​​the tank top structure. The extraction sampling head is connected to the centralized combustible gas analysis unit located in the analysis cabinet near the storage tank via a sampling pipeline. The centralized combustible gas analysis unit is controlled to sequentially switch the sampling channels of multiple sampling heads within a preset sampling period, and to perform polling analysis on the combustible gas concentration of each sampling channel.

12. The method for detecting combustible gas concentration in a heated storage tank area according to claim 11, characterized in that, The sampling pipeline is equipped with an external insulation layer and a heat tracing element to maintain the temperature of the sampled gas above 0°C to prevent condensation and freezing. The centralized combustible gas analysis unit is installed in an analysis cabinet with heat preservation and heating functions, and the ambient temperature inside the analysis cabinet is maintained within a first temperature range.

13. The method for detecting combustible gas concentration in a heated storage tank area according to claim 11, characterized in that, The step of acquiring the combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period includes: Obtain the combustible gas concentration output by the centralized combustible gas analysis unit for each extraction sampling channel.

14. The method for detecting combustible gas concentration in a heated storage tank area according to claim 13, characterized in that, The step of generating combustible gas concentration detection results for the cryogenic storage tank area based on the combustible gas hazard status includes: If the concentration of the combustible gas is higher than the preset concentration threshold, the monitoring area on the top of the tank will be set to an alarm state.

15. A combustible gas concentration detection system for a cryogenic storage tank area, characterized in that, include: The deployment module is used to deploy combustible gas detection units in the tank top monitoring area of ​​the cryogenic storage tank area based on a preset deployment strategy. The combustible gas detection units include point-type combustible gas detection units and area-type combustible gas detection units. The combustible gas detection units are used to detect two different height layers in the tank top monitoring area. The acquisition module is used to acquire the combustible gas concentration detection data output by the combustible gas detection unit within a preset detection period; The determination module is used to determine the flammable gas hazard status of the monitoring area on the top of the tank based on the flammable gas concentration detection data; The generation module is used to generate combustible gas concentration detection results for the cryogenic storage tank area based on the combustible gas hazard status.

16. An electronic device, characterized in that, include: processor; as well as, Memory for storing the executable instructions of the processor; The processor is configured to execute the method of any one of claims 1 to 14 by executing the executable instructions.

17. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1 to 14.

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